Wireless communication is used extensively and is still increasing. Users within a wireless communication network demand communication links that provide them with fast and uninterrupted data communication and ways of providing services to the users are constantly being developed and improved. Operators of wireless communication systems thus strive to offer the users high quality communication links with the scarce resources, e.g. particular frequency bands that are available to them.
Dual connectivity is a feature defined from the perspective of a wireless device, wherein the wireless device may receive from and transmit to at least two different network points, and thereby being provided with increased communication resources. The network point, e.g. a base station such as a eNode B, is a node enabling communication between a wireless device and the network. Dual connectivity is defined for the cases when aggregated network points operate on the same or separate frequencies. That is, the wireless device is connected to two or more network points, which may operate on same or separate frequencies. Each network point that a wireless device is aggregating may, but need not, define a stand-alone cell.
Dual connectivity as a feature bears many similarities with carrier aggregation and coordinated multi-point (CoMP). In CoMP, the wireless device transmits and receives data to and from several network points, and CoMP may improve the overall quality for the user as well as improve the utilization of the wireless communication network. A main differentiating factor is that dual connectivity is designed in consideration of a relaxed backhaul and less stringent synchronization requirements between the network points. This is in contrast to carrier aggregation and CoMP, wherein tight synchronization and a low-delay backhaul are assumed between the aggregated network points.
Besides providing users fast data throughput e.g. by offering several communication links, there are other aspects for obtaining high user satisfaction. One such other aspect is the provision of energy efficient operation, which for the wireless device translates into maximized battery operation time. Procedures defined up to date for connecting to a network point have been developed in view of maximized data throughput rather than energy efficiency.
It would thus be desirable to enable energy efficient operation of a wireless device while still offering fast data throughput.